the city of brotherly love. according to tmz, hemsworth had just left a bar, when he confronted this man who he thought had thrown a rock at him and his friend. >> his bad boy image may be appealing to some fans. people in the city don't like to see this type of thing. >> reporter: the victim can be seen clinging to his attacker's leg, while he takes a beating that only stops when a police car arrives. >> actually, he did. >> reporter: we've seen a glimpse of hemsworth's bad boy side before. back in 2009, he and his big brother, chris, reportedly got into a full-on fistfight with another man after an event in hltd. hollywood. that was around the time he started dating his now-fiancee miley cyrus, with bold care cuts and tattoos, has gained a rebellious reputation recently. as far as hemsworth's seemingly spontaneous event, witnesses say they never saw the victim throw the rock that allegedly started it all. for "good morning america," linsey davis, abc news, new york. >>> we're really excited about what is comin